Running tools are used the oil and gas service industry to install and retrieve equipment or components from wells, either at the wellhead, or downhole. One such use of running tools is in casing-drilling applications. With the onset of complex directional operations and long laterals, casing-drilling has become a preferred method for land wells. This operation requires the casing string to be rotated while drilling. A mandrel casing hanger may also be used to rotate the casing string during cementing of the casing strings in the well operation. Rotating the casing string has benefits, such as increased manoeuverability of the bottomhole assembly (BHA) and drill bit, better circulation and movement of the flow cuttings to the surface, increasing in strength of the pilot hole by packing the walls when cementing, faster and easier installations in horizontal well sections (laterals), less chance of sticking pipe in horizontal sections, and the ability to un-torque or torsionally relax the pipe once it reaches the desired depth. Running tools are used to engage the mandrel casing hanger, and can be used to rotate the casing hanger and the connected casing string during cementing of the casing string. Typically the casing hanger is supported in whole or in part on a load shoulder formed or provided in a casing head. During rotation the casing hanger can be lifted off the load shoulder and supported by a top drive during rotation. Various techniques exist to connect the running tool to the casing hanger and to rotate the casing hanger and the casing string, see for example US Published Patent Applications 2014/0311753 A1 and 2015/0041151 A1, both assigned to Cameron International Corporation and US Published Patent Application 2014/0305659 A1, assigned to Seaboard International, Inc.
In general, torque is applied at the running tool, and is translated through the mandrel casing hanger to the entire casing string to rotate the casing string. Depending on the direction in which the torque is applied, the threaded connection between the running tool and the mandrel casing hanger could be over tightened, making disengagement difficult, or the threaded connection may be backed out, which can drop the casing string or break the seal between the tubular connections.